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The object of the current invention is a device and a procedure for the atomization or nebulization of a liquid by using an impulsion gas or steam (hereinafter, gas) pressurized into such device. Both fluids are expelled to the outside after their mixture, causing the liquid to exit as a spray or suspension of droplets that is carried by the gas flow. The device consists of a liquid chamber, contained in a vessel or pressurized bottle, and a liquid-gas mixing zone, where the combination between both phases and their exit occurs. The impulsion gas gets into the bottle through an injection inlet, subsequently leaving such vessel through the mixing zone. The free surface of the liquid within the bottle is pressurized by the impulsion gas, causing the liquid to be impelled to the mixing zone through a feeding tube whose nozzle is close to the bottom of the bottle. At the other end of the feeding tube, called nebulizer end, there is an exit hole. Said exit section is approximately opposed to a vessel exit orifice, through which the mixed liquid/gas goes out to the outside as a suspension of droplets. Said exit orifice is perforated at the wall of the vessel. A key feature of the invention is that the internal edges of such exit hole and the external edges of such exit orifice define two closed lines in approximately parallel planes and separated by a short distance; the passage surface comprised between both edge lines is ring-shaped. The gas coming from the pressurized bottle that tries to escape to the outer environment, flows in a essentially radial and centripetal pattern in the surroundings of the mixing zone, leading to the cross flow with the liquid flow coming from the feeding tube. Immediately after passing through that ring-shaped surface, the gas intercepts said liquid flow at the perimeter and in an essentially perpendicular direction. The minimum passage section of the approximately radial flow of the exiting gas is indeed located at the ring-shaped surface; said minimum section has a surface of the same order as the section of the exit orifice. The feeding tube may have a pressure drop adjuster, which allows controlling the flow rate of the atomized liquid.
Nebulizers enable the transformation of a liquid in a spray or suspension of microdroplets. Nebulizers usually consist of a reserve tank where the liquid is introduced, a nebulization chamber where the spray is generated, and an energy supply, generally a pump, to impel the carrier gas of the suspension.
The atomization of liquids by purely fluid dynamics means, and particularly through pneumatic means, Ls an essential operation in multiple industrial, technological, scientific applications and developments and in the daily life. Sprays have been used in numerous technological fields, particularly as a way to treat diseases of respiratory tracks through the nebulization of liquid medicaments. Spray drug delivery by means of inhalation leads to the adequate medicament concentration in the respiratory track, min g secondary effects.
Applications in the agricultural field are also very extended for pesticide atomization, for instance in insecticide treatments. For that purpose, manual and automatic equipments are used (portable, vehicle mounted), allowing aim-targeted delivery and capability to control the drop size, whose diameter is usually between 100 and 500 microns. When drop sizes are smaller, between 50 and 100 microns, the term nebulization is commonly used: for insecticide applications, it increases the flotation capability of the preparation and also the liquid contact area when drop deposition takes place.
The atomization of liquids is based on diverse technological principles. These principles mark the quality and stability of the spray (monodispersity, drop size), as well as the use friendliness and procedure economy.
The so-called Flow Focusing (FF) technology (Gañán-Calvo 1998, Physical Review Letters 80, 285), uses an especial geometry and the pneumatic means to generate liquid microjets; after exiting through an orifice these microjets break up into droplets with a small and substantially homogeneous size. This technology is also able to generate liquid microjets using a liquid instead of a gas, or to generate a gas microjet within a liquid (the same liquid or other different used as the focusing, i.e., with the same role played by the gas in the pneumatic procedure), leading to the generation of perfectly homogeneous microbubbles.
Subsequently, the patent WO 0076673 (D1) proposed a configuration of flow, then called “Violent flow focusing”; unlike FF, the focusing gas has here an essentially radial and centripetal flow (diaphragm flow), concentrically directed as a thin layer that intercepts the exit of the liquid at a flow surface transversal to the axis of movement of the liquid. As explained in D1, the gas comes from a pressure chamber, and the intense interaction produced between the liquid phase, whose movement is essentially axial, and the gas phase, directed radially, give rise to an immediate transfer of momentum. However, in D1, the liquid issues to the outer atmosphere as a jet.
As it is shown in the description below, the differentiating aspects of the present invention, whose principle will be referred to as anti-flow focusing (AFF), in contrast with D1 (violent-flow focusing o VFF), are the following:
With regard to D1, of which the present patent is a later development, the hereby described invention introduces specifications to the design allowing the complete atomization of the liquid jet before its exit. It ensures at the same time a significant simplification of the design requiring only one pressurization element.
The present invention, belonging to the pneumatic atomizer field, intends to combine the advantages of a robust and simple design, with performance in continuous regime at low pressures by means of an impulsion gas that, in most cases, can be atmospheric air. The present invention allows using a gas-to-liquid mass flow ratio as low as one part of gas per seven parts of liquid, keeping an adequate atomization level of the liquid. Hence the device object of the present invention is very efficient from the energy point of view. The low energetic consumption of the device here described is compatible with a renewable energy source such as photovoltaic cell or wind power.
On the other hand, the patent “Nebulizador neumático de vílvila integrada” P200401504 (D2) shows an atomizing device with the same general configuration as here described, based on the same combined liquid and gas pressurization principle, with the following differences:
The gas exits the pressurization bottle through an outlet tube independent of the feeding tube through which the liquid exits. This outlet tube is superfluous in the present invention.
The device works in three flow regimes dependant on the position of the three way valve. Also this valve is superfluous with the present invention.
Below is described the method applied in the present patent, referred to as “Anti Flow Focusing” (hereafter AFF), which is suitable for the production of extremely thin aerosols and particles suspensions. This method originates from a later configuration of the flow that D1 describes as violent flow-focusing. In general, AFF is based in a geometric configuration that maximises the interaction between a liquid (dispersed phase) and a highly accelerated fluid (bearer phase). The AFF method optimizes the energy transference between both phases and, compared to other current pneumatic methods, reaches a significant increase of the proportion of energy used to generate surface in the dispersed phase.
Although any fluid, provided that it is sufficiently different from the dispersed phase (i.e. non mixable), can be used as bearer phase, usually this bearer phase will be air or any inert gas. Therefore, to simplify the description of the invention, from now on it will be referred to simply as “gas”, not intending by it any restrictions to the range of fluids that can be used as a bearer phase.
The liquid is led to the area where the interaction with the gas takes place by means of a hermetic transport means preventing premature mixing of the two phases. The shape of said liquid transport means may vary substantially with no impact on the operation of the AFF; only the exit shape may be marginally influent because this is the area where the interaction between the two phases takes place. In order to simplify the invention description, hereafter we will refer to this transport means as “tube”, thus not implying restrictions to the shape, number or configuration of the parts composing said transport means.
In AFF (see FIG. 4), a liquid flowing through a feeding tube (6) with a given flow rate, accesses through the exit hole (9) of said tube to a pressure chamber that is continuously filled in with gas. This pressure chamber has an exit orifice (3) through which the mixture of the bearer and dispersed phases exits. This orifice must be placed opposite to the exit hole (9) of the liquid tube and close to it, with a short axial difference between the facing edges of the orifice and hole, defining a section passage for the gas. The interaction between both phases takes place in the mixing region located between the mentioned hole and orifice. The gas that, owing to its pressure, tries to exit to the exterior, must cross previously that passage section defined by the ring-shape interval comprised between the facing borders of the exit orifice and exit hole; this fact drives the gas with an orientation essentially radial and perpendicular to the liquid movement axis when it exits the tube; this gas movement intercepting the liquid flow centripetally is named diaphragm-flow, the minimal passage section for the gas on its movement through this thin layer must have a surface substantially equivalent to the exit orifice (3) passage surface.
Due to this geometric configuration, the gas flooding the pressure chamber experiences a strong acceleration (changing abruptly both velocity and direction) when crossing the exit hole of the tube and meeting the axial flow of the liquid exiting the tube. Hence, the liquid exiting the tube experiences a violent implosion as a consequence of the intense radial and centripetal component of the gas interacting with it. This produces in the liquid in the exit section of the tube, a high pressure central area and, at the same time, a low pressure close to the inner border of the tube exit. As a consequence, a vorticity pattern is created in the liquid that produces the appearance of violent turbulent unsteady motion in the same exit area of the liquid of the tube. The intense shear stress interaction between both phases, liquid and gas, in the mixing area, together with the emergence of said violent turbulent motions of the liquid separate the liquid very efficiently into small droplets. The mixture of the two phases leaves the pressure chamber through the orifice (3) as a very dense aerosol characterized by having extremely small drops. The drop size distribution created depends basically of:
The bearer gas flooding the pressure chamber (see FIG. 1) experiences a pressure drop from the pressure in said chamber (p0) to the room pressure (pa); the gas reaches room pressure precisely in the exit section of the exit orifice (3) of the chamber. Thus, in the surroundings of the orifice (3) the gas pressure (p1) is higher but close to room pressure. If the exit hole of the tube of liquid is placed close enough to the chamber exit orifice (a necessary event when the gas passage section previously described between the tube and the orifice is equivalent to the exit orifice section) the gas pressure at the exit of the liquid tube will be smaller than the gas pressure in the pressure chamber in areas far enough from the orifice. Hence, if the liquid comes from a container connected to the pressure chamber (according to the joint pressurization principle) there is a pressure difference between the free surface of the liquid in the container containing it (p0, pressure chamber pressure) and the exit of the liquid tube (p1, pressure close to room pressure). Therefore, if the inlet of the tube (7) is immersed in the liquid of the container (1), the pressure difference between its ends (7 and 8) will cause the movement of the liquid through the tube, that is, the bearer gas “sucks up” the liquid and drives it to the interaction zone (4), where it is broken up into droplets and is then carried to the exterior of the chamber in the form of a fine aerosol.
With a configuration as described, only a single external energy source is required (pressurized gas) to produce the atomization, an external pumping system for the liquid being superfluous. In this configuration, the liquid flow rate is controlled through three parameters:
It is easier to control this third parameter because the first one would require modifying the device geometry, and the second changes with time (the height of the free surface decreases as the liquid is consumed). Through the interposition of local head loss, the liquid flow rate can be controlled precisely and, therefore, the characteristics of the aerosol obtained.
The method hereby described is shown to be extremely effective in the production of aerosols and suspensions, because it maximizes the interaction between the bearer and the dispersed phase. The efficiency of the atomization of the AFF, described as the proportion of the total energy introduced in the system (by the bearer gas) that is effectively used to the generation of the dispersed phase surface, reaches values much higher than those reached by other current pneumatic methods.
This geometry originates the following fact, essential for the invention: the pressure in the exit hole of the feeding tube (p1) is comprised between the values of the room pressure (pa) and the integral pressure of the gas and the liquid (p0).
The device and procedure object of the present invention lead to the production in continuous regime of a good quality aerosol with no need to turn to an impulsion gas other than atmospheric air or the steam coming from one single source. A light pressurization is enough to impulse the mixture of fluids and the atomization of the liquid. This ensures a very moderate energetic consumption, making the invention compatible with renewable and self-sufficient energy sources (sun collector, wind power).
The invention can as well be complemented with the following addition: the borders of the orifice and hole (10 and 11), or their nearby surroundings, can present some surface finish (roughness, sawing, undulation) with a typical dimension smaller than the average diameter dj of the liquid jet created in the exit orifice. This effect can be chosen among the following or similar effects:
Additionally, the height and amplitude of those carvings described above must be bigger than the thickness δ of the viscous boundary layer formed by the gas flow at the surfaces (10 and 11).
The existence of a carving on the borders (10 and 11) or their surroundings originates disturbances in the radial gas flow that absorbe a big amount of kinetic energy of the gas flow during its evolution when it is forced to implode radially on the liquid, interact with it, and change direction to exit through the exit orifice (3). This energy absorption takes place by means of a well known mechanism of flow instability development, that turn into turbulent fluctuations, whose evolution and growth are strongly non linear with time. As a consequence, the kinetic energy of the disturbances caused by said carving is transferred, by the known mechanism of turbulent flows, to the small scale disturbances, which finally break the surface of the liquid and separate it into small droplets.
In short, the particular features of the present invention are:
Next the embodiment of a real device is shown where the AFF technology has been successfully integrated (see FIG. 2). Said device is made of a two litre capacity plastic bottle (17), in whose opening there is a threaded lid (18), made out of plastic as well. The screw must be leakproof, by means of a sealant or a suitable o-ring. The gas coming from an external pressurization source is introduced through an opening (19) in the lid. In the present execution such pressurization source is an air diaphragm pump consuming 15 watts of power.
Also, there is a cavity (20, see detail) in the lid, where several parts are integrated:
All these parts are pressure fitted, ensuring there are neither relative movements among the parts nor unwanted leaks to the outside. The capillary tubing (22) is connected to the liquid in the bottle by a flexible Tygon® tube with a 0.3 millimetres of inner diameter and 2,5 millimetres of outer diameter.
The operation of the device is as follows: the gas accesses the bottle (2) through the opening (19) in the lid (18) and pressurizes the interior of the bottle. According to the physical phenomena described previously, said gas impulses the liquid contained in the bottle and forces it to raise through the tube (24) connecting the bottom of the bottle to the higher tip of the capillary (22), while the gas enters the pressure chamber to the mixing zone through one or several gas passage orifices (25) performed on the possitioner (23). According to the physical phenomena described previously, the gas and the liquid are mixed and give rise to an aerosol. In the lower tip of the tube (24), a localized head loss point is set (26), in order to control the flow rate of nebulized liquid.
This localized pressure drop (26) can be, for example, a tube 3 millimetre long, 0,1 millimetre of inner diameter and 1,5 millimetre of outer diameter, introduced at the tip of the Tygon tube.
General Configuration
The aim of the invention is a device for the atomization of a liquid by means of an impulsion gas or steam (from now on, gas (G)) that is pressurized into said device; both fluids are expelled to the outside as an aerosol or droplet suspension transported by said gas; the mentioned device consists of a liquid storage chamber (1), contained in a container or pressurized bottle (2) under joint gas and liquid pressurization pressure (p0); said container (2) is leakproof and includes an injection inlet (5) that allows the introduction of the pressurized gas; the container also includes an external exit orifice (3) for the gas/liquid mixture; the exit orifice is located in a mixing area (4) where the combination of both gas and liquid phases takes place, as well as the breakup of the liquid flow and its exit to the outside as an of aerosol; the impulsion gas, after entering the container (2) through the injection inlet (5), exits through said exit orifice (3) to the environment; the free surface of the liquid inside the container (2) is pressed by the impulsion gas, so that the liquid is therefore impulsed to the mixing area through a feeding tube (6); the aspiration inlet (7) of said feeding tube is located close to the bottom of the bottle (2); the other end of the feeding tube, the so called nebulizer end (8), consists of an exit hole (9) whose outer edge (10) is approximately facing the inner edge (11) of the exit orifice (3), there existing between both facing edges a short axial difference that defines a ring-shaped passage section for the impulsion gas; said exit orifice (3) is drilled in a wall of the container (2) and approximately located in a plane perpendicular to the axis of the nebulizer end (8); the gas coming from the pressurized bottle must cross radially said ring-shaped section comprised between the inner border (11) of the exit orifice (3) and the outer border (10) of the exit hole (9) before exiting to the outside through the mentioned exit orifice; said ring-shaped passage section is the minimal section in the radial trajectory of the gas and its area is of the order of the area of the exit orifice; the pressure in the exit hole of the feeding tube (p1) is comprised between the values of the external room pressure (pa) and the joint gas and liquid pressurization pressure (p0).
The aim of the invention is a device (FIG. 1) for the atomization of a liquid by means of an impulsion gas or steam (from now on gas (G)) that is pressurized into the mentioned device; both fluids are expelled to the outside as an aerosol or suspension of droplets transported by that gas; such device comprises of a liquid storage chamber (L) (1), contained in a container or pressurized bottle (2) at the pressure (p0) of integral pressurization of the gas and liquid; that container is leakproof and includes an injection inlet (5) that permits the entry of the pressurized gas; the container also has an exit orifice (3) for the mixture gas/liquid; that exit orifice is placed in a mixing area (4) where the two phases gas and liquid are combined, leading to the breakup of the liquid flow and the exit to the outside as an aerosol; the impulsion gas, after entering the container (2) through the injection inlet (5), exits through another exit orifice (3) to the environment; the free liquid surface inside that container (2) is pressed by the impulsion gas to the mixing area through a feeding tube (6), whose aspiration inlet (7) is placed close to the bottom of the bottle (2); the other end of the feeding tube, called nebulizer end (8), comprises of an exit hole (9) whose outer border (10) is approximately facing the inner border (11) of that exit orifice (3); between both facing borders there is a small axial gap (e) that defines a ring-shaped passage section for the impulsion gas (see detail of FIG. 1); that exit orifice (3) is drilled on a wall of that container (2) that is approximately located on a perpendicular plane to the axis of that nebulizer end (8); the gas coming from the pressurized bottle has to cross radially the ring-shape passage section between the inner border (11) of the exit orifice (3) and the outer border (10) of the exit hole (9) to go to the outside through that exit orifice; the ring-shape passage is the minimal section in the radial path of the gas and has a surface of the order of the section of the exit hole; the pressure at the exit hole of the feeding tube (p1) is comprised between the values of outer room pressure (pa) and the integral gas and liquid pressurization pressure (p0).
Different Configurations of the Exit Orifice and Exit Hole
In particular, it is also in the scope of the present invention a design as follows: the outer face of the wall of the container in the surroundings of the exit orifice (3) is carved to create an approximately conic crater (see FIG. 5), whose edge coincides with the inner edge (11) of the orifice section in the inner face of said wall. Thus, the orifice walls are not parallel to the axis itself, but they form a certain angle with the orifice axis.
It is also in the scope of the present invention a device for the atomization of a liquid by means of an impulsion gas according to the above mentioned where the orifice and hole edges (10 and 11), or their close surroundings, can present some surface finish effect (roughness, sawing, undulation) of a characteristic size smaller than the average diameter dj of the liquid jet flowing through the exit orifice after the liquid exits said exit hole (9), and higher than the thickness of the boundary of the gas at the solid walls.
Configuration of Two Chambers with Exhaust Valve
It is also in the scope of this invention a device with a configuration (see FIG. 3) alternative to the general configuration described previously. The new features of this configuration are: (i) the gas pressure chamber is sub-divided by a partition wall (12) into two new ones, higher (13) and lower (14), that are connected through a connection port (15); (ii) all the liquid is contained in the lower chamber, where there is a gas purge valve (16) opening to the environment. This configuration presents some advantages compared to the configuration described previously, in particular providing a stronger control on the nebulization and the integration of a purge or cleaning procedure in the same device.
The performance of this particular configuration is based on the pressure difference between the higher chamber (13) at pressure p0A, and the lower chamber (14), at pressure p0B. This pressure difference is due to a pressure drop experienced by the gas when it crosses the connection port (15) existing on the wall (12). According to the opening status of the valve (16) we can see two different performance conditions:
Therefore the configuration with two chambers and exhaust valve allows controlling with precision the duration of the nebulization (start and stop), its characteristics and it also integrates a cleaning or purges functionality.
In relation to the other described elements, it must be emphasized that there are no restrictions neither in the nature and characteristics of the wall (12) that separates the higher chamber (13) from the lower (14) nor in the connection port (15) that joins both chambers. They can be as simple as a plate with a single orifice, one plate with multiple orifices located in any configuration (reticular, circular, etc.), a filter of a determined pore size or any other separation media allowing to achieve the desired pressure drop. Though the simplest configuration consists of fix and immobile structural elements, this does not avoid the usage of any element or assembly of elements with one or several mobile parts driven manually or automatically (i.e. valves controlled electronically from the outside). Any solution is possible as long as both chambers are separated in a way that produces the desired pressure drop of the gas when it crosses the connection port (15).
Given the relative position of the two chambers or compartments, being all the liquid contained in the lower compartment, we need to restrict in this configuration the inclination of the bottle while it is in use. As an alternative solution, it is possible to design the connection port between the two chambers with a device that prevents the passage of liquid from the lower to the higher chamber.
Configuration with Three Chambers and Exhaust Valve
This configuration (FIG. 4) is a variation of the previous one, where the higher compartment (13) is sub-divided into two receptacles: a pressurization receptacle (13a) connected directly to the pressurized gas inlet (5) and an impulsion receptacle (13b), surrounding the mixing area; both receptacles are connected to each other through a second connection port (15a) that creates a pressure drop in the gas flow between both receptacles. The aim of this division in three chambers is to increase the control options of the device, especially in regard to the pressure distribution in the mixing area (FIG. 1, detail.
Configuration with Removable Liquid Container
It is also in the scope of this invention a device (FIG. 6) in which the pressurized container comprises two parts assembled to each other. The first of them is a chamber (27) full with gas where the mixing area for the gas and liquid is integrated. The second part is a container for the liquid (28) which is assembled to the previous one by any joining mean ensuring that it remains fixed and leakproof (thread, pressure adjustment, etc.). The gas is introduced in the device through a inlet (5), which can be integrated both in the chamber (27) and in the liquid container (28). The liquid container can be used again after cleaning it or be disposable capsules. In the usual case where the liquid is atomized with a gas (and in general, whenever the bearer phase is less dense than the dispersed phase), the gas entry to the container can even be done under the free surface of the liquid, so that the gas will produce bubbles in the liquid that will later raise and pressurize the area above the free surface of the liquid. This pressurized gas impulses the liquid from the container (28) to the mixing area (4) through a tube for liquid transport (29).
In another version of the invention, the container (28) has a valve and is separated from the chamber (27) by means of a wall where there is a connection port such as it was explained before for the general device with two chambers and an exhaust valve. Thus, in this device all advantages of the two chambers with exhaust valve configuration add up (cleanliness possibility, nebulization control, etc.) and the possibility to disassemble the liquid container as desired for cleaning or charging purposes.
Pressure Drop Control
In another version of the invention, the feeding tube (6) incorporates a pressure drop control. This pressure drop control, which can be included in any of the described devices, may consist of a simple fix obstacle to the passage of liquid (i.e. a stretch of tube of small diameter, a filter with the adequate pore size, a frit, etc.) or else it can be an element with variable pressure drop (i.e. a valve controlled externally.
Impulsion Gel Steam
In this version of the invention the pressurized gas used to produce the atomization is a steam (V) obtained from a vaporizable liquid (Lv). Without this meaning a restriction to the liquid, that vaporizable liquid can be chosen among the following substances or their combinations: water CFCs, alcohols, ketones, ethers, esters, paraffins, alkanes, cycloparaffins, naphthenes or cycloalkanes or aromatic hydrocarbon, olefins, alkenes and other non saturated hydrocarbons.
In general, the vaporization of the vaporizable liquid is done by applying heat. Applying heat can be done externally, in a container independent from the device body (FIG. 7), where the liquid to be atomized (La) is stored separately.
As an option, both liquids, atomizable (La) and vaporizable (Lv), can be stored together in the device (FIG. 8) using an adequate separation; then applying heat will heat up both liquid to be vaporized and liquid to be atomized. Typically, the bottle or pressurized container (2) is surrounded (as a Thermos bottle) with a layer for vaporizable liquid storage. The common heating of both liquids vaporizes though only one of them, the one contained in the outer layer that being already in vapour phase, enters the interior of the pressure chamber through the inlet (5). This method requires the boiling point of the vaporizable liquid to be sufficiently smaller than the boiling point of the liquid to be atomized.
In this configuration, generally the temperature of the two liquid phases previous to their vaporization or atomization is approximately the same.
In this configuration, the caloric power supplied to keep the temperature common to both liquid phases can be used as control parameter of the pressure and the vapour flow rate introduced under pressure through the injection inlet (5).
An alternative option involves using as raw material in the device a solid to be atomized. For that it is required to achieve its phase change, generally by heat application. The solid can be introduced as grain, powder, bars or lumps. The most favourable configuration is achieved when the solid phase to be turned into atomizable liquid and the vaporizable liquid to be turned into impulsion vapour are stored together with the appropriate separation (of the double wall thermal bottle type), and they are heated simultaneously to a temperature almost-common to both of them to ensure the production of the working conditions.
The caloric power applied to keep a common temperature in both liquid phases is also used as a control parameter of the surface tension and the viscosity of that liquid to be atomized. These properties, in fact, are essential for controlling the drop size.
Application
Finally, the invention includes a procedure for the atomization of a liquid by means of an impulsion gas according to the devices described in the paragraphs above.
This procedure can be use for different aims: in one of the foreseen cases, the aerosol or drop suspension produced is used for humidification or air conditioning of spaces, both interior and exterior.
In the case of mixing the liquid to be atomized with some additives, the aerosol can be used for air conditioning, air freshening, balsamic substances dispersion, disinsecting, biologic control of airborne infectious transmission illnesses and other applications where atmospheric air constitutes the basic transport vehicle of droplets or their rests (after the evaporation of the liquid or solvent) to the target final areas, that can be the respiratory system of any living being, its outer skin, or its eyes.
When the liquid contains pigments, polymers, monomers or other substances such as paintings, polishes, ceramic or metallic particles, oils or outer skins of any nature, those target final areas can also be of any kind that is wanted to be treated by deposing those mentioned substances on those surfaces.
In another foreseen application, the aerosol or drop suspension produced is used for food production.
In another application explicitly included, the liquid is a fuel and the gas is a comburent, and the aerosol or droplet suspension gas produced is used as mixture in an internal combustion engine.
It is as well foreseen another application in which the aerosol is used to refrigerate the machining area and the tool in any machining operation of a metallic, polymeric or ceramic material.
In an additional foreseen application, the aerosol is used as volumetric collecting mean for powder, particles of all nature or molecules suspended in the media where the aerosol is dispersed.
FIG. 1: General drawing of the AFF device with joint pressurization.
In this drawing the gas (G) is introduced into the pressurized container (2) through the inlet (5). The pressure of the gas impulses the liquid (L) contained in the storage chamber (1) and drives it through the tube (6) up to the mixing area (4) where it interacts with the gas producing an aerosol that exits to the outside through the exit orifice (3).
FIG. 1 (inferior detail): main geometry of the invention in the mixing area (4) including the inlets of liquid and gas, the exit of the mixture and the edges 10 and 11. The liquid flow is intercepted radially in perimetrical flow pattern. This is therefore a perimetrical cross-flow where a gas diaphragm-flow strangulates a liquid jet.
FIG. 2: Drawing of manufactured device.
In this drawing the gas (G) enters a plastic bottle (17) through the opening (19) and impulses the liquid (L) contained in the storage chamber (1) to the mixing area along a feeding tube (24) firstly and the capillary tubing (22) afterwards. In this area the liquid interacts with the gas producing an aerosol that exits to the outside through the exiting orifice on the plate (21). The detail (*) shows a mixing area according to the description in FIG. 1.
FIG. 3: Drawing of device with two chambers and an exhaust valve.
In this figure the gas enters the container (2) through the inlet (5) and pressurizes the higher chamber (13) and the lower chamber (14) to the pressures p0A and p0B. These pressures are determined by the pressure drop experienced by the gas when crossing the connection port (15) and the exhaust valve (16). In case the valve is closed, the pressure in the lower chamber impulses the liquid through the tube (6) to the mixing area (4) where it interacts with the gas and forms the aerosol exiting to the outside through the exit orifice (3). On the contrary, if the valve is open, the introduced gas exits to the outside through the exit orifice (3) and the valve itself (16); the pressures created in the higher and lower chambers produce a pressure difference between the superior and inferior ends of the tube (6), so that the liquid contained in it circulates back to the storage chamber (1).
FIG. 4: Drawing of device with three chambers.
This drawing is similar to the device described in the previous figure, but the high compartment is sub-divided into two containers (13a and 13b), separated from each other by a second connection port (15a). The pressure drop associated to this second port allows adjusting the pressure (p0C) in the higher chamber and therefore, the pressure (p1) in the mixing area (4).
FIG. 5: Particular configuration in which the outer walls of the orifice form an angle θ with its axis.
FIG. 6: Drawing of a device characterized by a joint pressurization chamber where the gas and liquid are placed, consisting of two removable parts (27, 28), all of the liquid being contained in one of them (28). The gas is introduced through the inlet (5) and impulses the liquid from the liquid storage chamber (1) to the mixing area (4) through the transport tube (29).
FIG. 7: Drawing of device with external vaporizer.
The vaporizable liquid (Lv) contained in the vaporizable liquid chamber (30) is heated by supplying an amount of heat (Q). The produced vapour (V is driven to the inlet (5) and accesses the inside of the bottle (2). The vapour is used to impulse the atomizable liquid (La) to the mixing head (31), where it is mixed with the vapour producing the aerosol.
FIG. 8: Drawing of device with joint vaporizer.
The supplied heat (Q) is used on the one hand to heat the liquid to be vaporized (Lv) and to play the role of an impulsion vapour (and, at the same time, to heat the liquid to be atomized (La).
The impulsion vapour and the impulsed liquid reach the mixing head (31) and they are mixed producing the aerosol. As an option, the atomizable liquid (La) is in solid phase before being heated.